8 rounds of 20 seconds work and 10 seconds recovery. Named after person who created it in testing athletic performance of sprinters. The 20 seconds has got to be all out so it’s important to choose correct activity but only after assessing if your conditioning qualifies to to do something like this.

Aside from sprinting, I thing burpees are great for a quick 4-minute Tabata workout.

Strictly speaking, Tabata is not an exercise, its an exercise pacing strategy. As others said, it's a particular variety of high intensity interval training (HIIT).

Personally, I think it's goofy that there are Tabata classes, because lots of things can be done with Tabata pacing (cycling, running, rowing, etc.) Most of the time, the classes seem to be some kind of calisthenics or circuit training routine.

They may or may not fit the original technical definition of Tabata or HIIT, but can be good exercise either way.

Basically it's a high intensity interval training protocol.
I go to classes and my PT often uses the same protocol in our sessions.
Its 20sec all out, followed by 10sec rest for 8 rounds. You can use all sorts of different exercises. Sometimes we box, sometimes its sprints, or burpees, squat jumps, scissors or maybe Jacks. I usually feel like I'm dying by the end of the 4 minutes and by halfway through the class or session I hate her, but always have a high by the end knowing I've survived.

Most "tabata" classes use the actually tabata protocol which was used to measure VO2 max in elite atheletes. If they did, everyone would be entirely wasted after the 1st set.

Whatever they offer is some sort of interval training but it is almost certainly will be far less demanding than a true tabata routine. So, calling them "tabata" classes is a misnomer and gross misrepresentation.

8 rounds of 20 seconds work and 10 seconds recovery. Named after person who created it in testing athletic performance of sprinters. The 20 seconds has got to be all out so it’s important to choose correct activity but only after assessing if your conditioning qualifies to to do something like this.

Aside from sprinting, I thing burpees are great for a quick 4-minute Tabata workout.

OP, I don't know what a "Tabata Class" is, but we occasionally do Tabata work towards the end of an indoor cycling class. As noted above, it's eight rounds of 20 seconds "all out" and 10 seconds of recovery pace. When done properly, this 4 minute block is extremely challenging.

A more tolerable protocol for more people is Sprint 8 as designed by Phil Campbell. After an obvious warmup, 8 rounds of 30 seconds hard work with 90 seconds of recovery. I did these with hill sprints but any kind of running or high-end anaerobic work will work. It’s a more do-able protocol than Tabata, based in my experience.

Most "tabata" classes use the actually tabata protocol which was used to measure VO2 max in elite atheletes. If they did, everyone would be entirely wasted after the 1st set.

Whatever they offer is some sort of interval training but it is almost certainly will be far less demanding than a true tabata routine. So, calling them "tabata" classes is a misnomer and gross misrepresentation.